Grade Compensation in Road at Curves
When a horizontal curve is introduced on a road in addition to the gradient, there will be increasing resistance to friction due to both gradient and curve. In such cases then the gradient should be decreased to compensate for the loss of tractive effort due to curve. This reduction in gradient at the horizontal curve on road is called grade compensation.
Grade Compensation Formula
Grade compensation at curve is calculated from the following formula or say relation.
1. Grade Compensation in road (%) = (30+R)/R
2. The maximum value 75/R %. Where R is the radius of the curve in m.
Note: According to I.R.C the grade compensation is not necessary for gradient flatter than 4%.